No. AP can pick up stories from member newspapers providing they were written by the staff of that paper. In the US all material that appears in a newspaper is copyrighted by that newspaper - there is no special process required. Generally when a newspaper puts the word "copyright" along with the byline it's just to call more attention to that story as being some sort of special report. Stories written by freelancers for one-time publication rights are owned by that writer and can't even be freely picked up by the wires - permission/sale must be arranged with the writer. So no, every newspaper is not free to pick up a story from another newspaper and run it verbatim.